How we moved from a fragile loop-based payout system to a reliable, idempotent, and traceable architecture. On paper, payouts sound simple: Customer places an order Platform collects payment Platform pays the seller That's it. Until you try to do it at scale. In any marketplace or fintech system, money flows across multiple parties: Sellers / vendors Delivery partners Platform fees Discounts, vouc
Building a Full-Stack Habit Tracker with Claude Code - Part 2: Polish, Testing & Deployment Taking the habit tracker from MVP to production-ready with categories, analytics, comprehensive testing, and Vercel deployment In [Part 1], we built a fully functional habit tracker MVP in about 6-8 hours using Claude Code as our AI pair programmer. We had: ✅ Basic CRUD operations for habits ✅ Date-based
Testing Firefox Extensions with Playwright: End-to-End Testing Guide Extension testing is one of those things everyone knows they should do but few actually do. I've been using Playwright for end-to-end tests on the Weather & Clock Dashboard extension and it's changed how I think about extension quality. Unit tests don't cover the biggest failure modes: Does the extension actually load in Firefo
The most basic concept in test doubles is the dummy. When testing a function, there are usually two kinds of input: Meaningful input Data that affects the result of the function. Dummy input Data that is required by the function, but does not affect the behavior we are testing. Below is an example of meaningful data vs dummy data. This is a calculateShipping function: function calculateShip
Your application fetches a URL. The user supplied it. Your server makes the request, follows the redirect, and returns the content. The URL pointed to http://169.254.169.254/latest/metadata/iam/security-credentials/production-role. Your application just handed the attacker your cloud credentials. SSRF lets an attacker trick your server into making requests on their behalf — to internal services, c
How to Test Firefox Extensions Without Publishing: Local Development Tips Publishing to AMO every time you want to test a change is slow and painful. Here's the full toolkit for local development. The fastest way to load your extension: Open Firefox and go to about:debugging Click This Firefox in the left sidebar Click Load Temporary Add-on... Navigate to your extension folder and select manif
I still remember where i was when the email came in. December 25th. Christmas morning. Phone in hand while having breakfast, and there is an email from our client's CTO. No greetings, Just "We're terminating the contract. Our legal team will be in touch" We lost a 120K a year contract. On a Christmas morning because of a date calculation bug that none of us, not a person on a team of 5 experienced
published: true description: "A developer's honest review of TestSprite: the autonomous AI testing agent that generates, runs, and patches tests for you. Including locale handling observations." tags: testing, ai, webdev, devtools cover_image: https://storage.googleapis.com/runable-templates/cli-uploads%2FgcLrVl9Cg6BLWTHb6clQeDzRFGBCNd4h%2F1kCxrovt5t9apSMJWdkFB%2Ftestsprite_hero.png I've been buil